In 2002, to experience augmented reality was to lash 26 pounds of equipment to your body and hobble waywardly within the confines of predefined area. In 2010, you can augment the entire world with a free app for your smartphone.

This shot of the Columbia University's Mobile Augmented Reality System (MARS) comes from a PopSci story written 10 Februaries ago. (The magazine's searchable archives just went online.) This right around the time that augmented reality had made the jump from esoteric sci-fi concept to actual thing, albeit in the form of awkward research projects and simplistic military applications:

If you strap on this rig, as [the writer] had, you begin to understand the profound possibilities of an AR system, which can superimpose computer-generated text, graphics, 3D animation, sound, or any other or any other digitized data on the real world.

As much as modern smartphone apps like Layar actually do more—they're connected to the internet constantly, for one—they still don't meet one of the core criteria of the augmented reality concept: they're not glasses. In other words, you've got to hold your smartphone out in front of you, as if you're taking a video at all times, which is as obnoxious as it is exhausting to your upper arms. So it's not quite sci-fi.